1. Field of the Invention
The present invention relates to a construction machine having an upper slewing body, wherein the upper slewing body comprises a frame bottom plate configured as a bottom wall thereof and formed with a downward opening.
2. Description of the Background Art
Generally, a construction machine, such as a hydraulic shovel, has a lower propelling body, and an upper slewing body provided on the lower propelling body to house various devices, such as an engine. The upper slewing body comprises a frame bottom plate configured as a bottom wall thereof and formed with a downward opening, that is, an opening opened downwardly so as to allow the devices to be inspected, and an undercover detachably attached to the frame bottom plate so as to close up the opening.
JP 2004-17928 A discloses a construction machine having such a frame bottom plate and such an undercover as is described above. The undercover disclosed in this publication is disposed under a hydraulic unit or a hydraulic pipe housed in an upper slewing body, and has a shape bulging downwardly from a lower surface of the frame bottom plate so as to be capable of retaining oil which leaks out of the hydraulic unit and others inside the undercover.
The shape thus bulging downwardly from the lower surface of the frame bottom plate, however, increases frequency of collisions of sand, rubble or the like raised from the ground with the undercover during traveling or during slewing of the upper slewing body, thereby making the undercover be likely to be damaged. Reversely, in the case of an undercover formed in a flat plate shape extending along the lower surface of the frame bottom plate so as to avoid the above damage, the undercover cannot have sufficient rigidity, which generates the possibility of occurrence of deformation of the undercover or large vibration noise therefrom.